/**
 * @Author Big_white
 * @Date 2021/11/11
 */
public class Projector {
    private static Projector instance=new Projector();
    public static Projector getInstance(){
        return instance;
    }
    public void on(){
        System.out.println("Projector on");
    }
    public void off(){
        System.out.println("Projector ff");
    }
    public void focus(){
        System.out.println("Projector is Projector");
    }
}
